This invention relates to serving windows and more particularly, to serving windows and similar openings installed in drive-through or walk-up facilities such as fast foot restaurants to facilitate exchange beteen the customer and the business without exposing the server to risk from the customer or the weather. Such windows are usually mounted in the wall of a facility at a height which will put the server in convenient reaching distance from a customer seated in a vehicle, and are commonly used for fast food restaurants and other businesses with drive-through service.
The windows presently in use in most drive-through facilities operate by use of a cable/pulley or block and tackle mechanism mounted within the bottom frame of the window unit and have frequent breakdowns due to the extreme wear and tear caused by continuous opening and closing of the windows. These equipment breakdowns and repairs or replacements are costly for the business owner both in equipment costs and "down" time for repairs.
The present invention responds to the disadvantages set forth above by employing a pivotal operating mechanism self-contained within the framework of the window unit and directly attached to the two window shafts. There are no belts or straps to break or stretch and the stress-tested mechanism gives greater reliability, is of higher quality, and costs less to install and maintain.
Additionally the unit of the present invention is easy to operate and offers a variety of enabling devices, including electrical with battery back-up, or body, hand or foot activated. A preferred embodiment is operated by means of an upholstered bump bar at hip level which fully opens the windows upon a two-inch movement of the bump bar. All of the enabling devices provide automatic closure of the windows upon release of pressure.
It is, therefore, the primary object of this invention to provide a service window with an operating mechanism that does not have the disadvantages heretofore recited and which is capable of effectively opening and closing the service window repetitively with minimal breakdown and replacement of parts, and with ease and variety of operation.
It is a further object of this invention to provide a service window wherein an operating mechanism is provided that is contained within the bottom support frame of the window.
A more particular object of this invention is to provide an operating mechanism for a service window, as aforesaid, which comprises a horizontal crossbar secured at its midpoint to the underside of the support frame by means of an arrangement that allows the crossbar to freely pivot on an upright axis, and connected at each end to cranks on the shafts of the window members, whereby the crossbar oscillates in response to pressure on the enabling means to synchronously open and close the windows.
Another object of this invention is to provide an operating mechanism for a service window, as aforesaid, wherein the crossbar is connected adjacent one end with a push/pull operating rod so that force on the rod applied by an enabling device causes the crossarm to swing and thereby open the window members of the window unit.
Yet another object of this invention is to provide an operating mechanism for a service window, as aforesaid, wherein the crossbar is stabilized by impact-reducing springs, so that sudden or excessive force on the operating rod does not over extend and damage the windows or operating mechanism, the force of movement of the windows being accordingly limited and cushioned by the action of the springs. The push/pull rod may extend through the bottom frame where it would be connected to a horizontally mounted, cushioned bump bar, or it may be fastened to a cable extending from the frame to the floor for attachment to a foot pad.